1. Field of the Invention
The present invention relates to a device for disconnecting the receiver in the case of a small signal-to-noise ratio for a digital-modulated radio system, in particular a radio system for transmitting communications between transmitting/receiving stations which move along predetermined paths and transmitting/receiving stations arranged at predetermined intervals along these paths.
2. Description of the Prior Art
In a radio system of the type mentioned above for the transmission of communications between transmitting/receiving stations moving along predetermined paths and transmitting/receiving stations arranged at predetermined intervals along such paths, as is known for example through the German published application No. 26 44 206, which corresponds to U.S. Pat. No. 4,209,749, and which is fully incorporated herein by this reference, a plurality of stationary transmitting/receiving stations can receive identical communications signals from a mobile transmitting/receiving station. A plurality of stationary transmitting/receiving stations can be connected in parallel in respect of their receiver outputs, so that those transmitting/receiving stations which are currently not receiving any item of communication as a result of the transmission emit a fixed zero level, although the communications signal of those transmitting/receiving stations which are currently receiving communications is not disturbed. Also, however, if a predetermined minimum signal-to-noise ratio S/N is undershot as a result of the transmission, the individual transmitting/receiving stations are to emit the output signal zero. As in the case of mobile radio systems, very rapid level fluctuations naturally occur, so that the disconnection procedure must also be sufficiently rapid relative to the data rate of the binary communication which is to be transmitted.